bricked psp 1001

Well, I haven't started a thread here in a long time but I need some help and I'll take all the advice I can get.

I was updating a PSP 1001 from 2.71 OFW to 5.03 OFW. About 13% through the update I received an error saying the memory card couldn't be read. There was nothing I could do to get it to continue so I was left with a brick. I have watched several videos on how to unbrick but most seem to require a CFW installed or a store purchased MMS. I have another PSP, a Pandora battery and a memory card so I'm hoping to be able to do something with this but so far everything has failed. No matter what I do, I can not get it to boot up even after creating a MMS (not sure I am doing everything required).